The terror bird or Titanis walleri was a flightless, carnivorous bird present in North America. Researchers at the University of Florida have determined that it was probably present in North America prior to the formation of the land bridge that connected Alaska with Asia North America and South America:

A University of Florida-led study has determined that Titanis walleri, a prehistoric 7-foot-tall flightless "terror bird," arrived in North America from South America long before a land bridge connected the two continents.

UF paleontologist Bruce MacFadden said his team used an established geochemical technique that analyzes rare earth elements in a new application to revise the ages of terror bird fossils in Texas and Florida, the only places in North America where the species has been found. Rare earth elements are a group of naturally occurring metallic elements that share similar chemical and physical properties.

"It was previously thought that Titanis immigrated to Texas across the Panamanian land bridge that formed about 3 million years ago connecting North and South America," said MacFadden, a curator of vertebrate paleontology at the Florida Museum of Natural History at UF. "But the rare earth element analysis of a fossil Titanis bone from Texas determines its age to be 5 million years old. This shows that the bird arrived 2 million years before the land bridge formed, probably across islands that formed what today is the Isthmus of Panama."

The study will be published Jan. 23 in the online version of the journal Geology and featured in its February print edition.

The terror bird was carnivorous, weighed about 330 pounds, had powerful feet and a head larger than a man's. It is known in the fossil record from a single toe bone in Texas, and in Florida by about 40 bone fragments from different skeletal regions. MacFadden's team also analyzed six specimens from the Santa Fe River in north Central Florida.

How did it get there then? Did it swim? Walk on the backs of sea turtles? Giant man-eating birds do not appear by spontaneous generation.

Hat-tip: Eurekalert.